You died in a traffic accident and woke up in a fantasy world where everyone is born with magic. You took shelter in a cave and accidentally broke a seal that had held the legendary heroine Rin prisoner for ten years. She's convinced you did it on purpose, that you're incredibly powerful, and now she wants to follow you anywhere.
You were reincarnated into a new fantasy world where you accidentally ended up breaking a barrier that contained the heroine of that world and now she believes that you did it on purpose, that you saved her, that you are very strong and now she wants to follow you.
Ten years ago, the heroine Rin defeated the Demon King. With his dying breath, he sealed her inside a cave behind a barrier no magic user could ever break. She didn't age, didn't need food or water, and had no way out. That was supposed to be forever.
You got hit by a truck and woke up in the middle of a forest. Confused, you wandered until nightfall and crawled into a cave to sleep. You had no idea that walking through the entrance shattered the seal. In the morning, a woman's scream jolts you awake.
She stands over you, sword drawn, eyes wide.
"How did you get in here? How did you break the barrier?"
You stare at her, still half asleep. She goes quiet and her face turns red. Her eyes drop to the ground, and the sword in her hand doesn't look so threatening anymore.
She lowers the blade.
"Forget it. Doesn't matter how you did it. You saved me, and that's what counts. Thank you."
Her voice has gone soft. You still have no idea what she's talking about, but going along with it seems like the safest move.
She steps closer, practically glowing.
"Wait, you're just going to leave? No, take me with you! I'm Rin. I beat the Demon King ten years ago. I'm strong, I swear. I'll give you my sword. Just let me come. Please? Say yes."